scholarly journals Gold Coated VO2 Nanogratings Based Plasmonic Switches

2022 ◽  
Vol 19 (1) ◽  
pp. 1721
Author(s):  
Priyanka Bhardwaj ◽  
Manidipa Roy ◽  
Sanjay Kumar Singh
Keyword(s):  
Optical Switching ◽  
Optical Switch ◽  
Field Enhancement ◽  
Metallic Phase ◽  
Ir Radiation ◽  
Fast Switching ◽  
Rigorous Coupled Wave Analysis ◽  
Current State ◽  
Plasmonic Switch ◽  
Rigorous Coupled Wave

This paper presents 2 dimensional (2D) and 1 dimensional (1D) gold (Au) coated VO2 (Vanadium Dioxide) nanogratings based tunable plasmonic switch. VO2 is a phase changing material and hence exhibits phase transition from semiconductor to metallic phase approximately at 67 ºC or 340 K (critical temperature) which can be achieved by exposure to IR radiation, application of voltage, heating, etc. and there is a huge contrast between optical properties of its metallic and insulating phases and hence that can be utilized to implement VO2 based optical switches. These VO2 based gratings couple the incident optical radiation to plasmonic waveguide modes which in turn leads to high electromagnetic field enhancement in the gaps between the nanogratings. The proposed Au coated VO2 nanogratings can be fabricated by using current state of art fabrication techniques and provides switchability of the order of femtoseconds. Hence the optical switching explained in our paper can be used fast switching applications. For an optimum switch our aim is to maximize its differential reflectance spectra between the 2 states of VO2, i.e., metallic and semiconductor phases. Rigorous Coupled Wave Analysis (RCWA) reveals that wavelengths for maximum differential reflectance can be optimized over a large spectral regime by varying various parameters of nanogratings for example groove height (h), width (w), gap (g) between the gratings, and thickness (t) of Au coating over VO2 by simulation using RCWA for maximum differential reflectance between VO2 metal and semiconductor phase, i.e., the switching wavelengths can be tuned by varying grating parameters and thus we can have optimum optical switch.

scholarly journals Tunable Infrared Optical Switch Based on Vanadium Dioxide

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2988
Author(s):  
Qi Wang ◽  
Shijie Zhang ◽  
Chen Wang ◽  
Rui Li ◽  
Tianhan Cai ◽  
...  
Keyword(s):  
Thin Film ◽  
Vanadium Dioxide ◽  
Optical Switching ◽  
Modulation Depth ◽  
Optical Switch ◽  
Extinction Ratio ◽  
Infrared Region ◽  
Metallic Phase ◽  
Ultrafast Switching ◽  
Difference Time

A tunable infrared optical switch based on a plasmonic structure consisting of aluminum nanoarrays with a thin film of vanadium dioxide is proposed. This optical switch can realize arbitrary wavelength-selective optical switching in the mid-infrared region by altering the radii of the aluminum nanoarrays. Furthermore, since vanadium dioxide transforms from its low-temperature insulator phase to a high-temperature metallic phase when heated or applied voltage, the optical switch can achieve two-way switching of its “ON” and “OFF” modes. Finite-difference time-domain software is used to simulate the performance of the proposed infrared optical switch. Simulation results show that the switch offers excellent optical performances, that the modulation depth can reach up to 99.4%, and that the extinction ratio exceeds −22.16 dB. In addition, the phase transition time of vanadium dioxide is on the femtosecond scale, which means that this optical switch based on a vanadium dioxide thin film can be used for ultrafast switching.

Design and Analysis of Optical-Communication-Band Sub-Wavelength Grating Polarizer

2013 ◽  
Vol 683 ◽  
pp. 207-210
Author(s):  
Er Fei Cai ◽  
Yong Qing Huang ◽  
Xiao Feng Duan ◽  
Xiao Min Ren
Keyword(s):  
Diffraction Efficiency ◽  
Optical Communication ◽  
Optical Switching ◽  
Optical Memory ◽  
Optical Detectors ◽  
Rigorous Coupled Wave Analysis ◽  
Te Mode ◽  
Communication Devices ◽  
Rigorous Coupled Wave ◽  
Sub Wavelength

According to the requirement of the optical communication devices, sub-wavelength grating polarizer was studied based on rigorous coupled-wave analysis (RCWA) and designed with SOI materials. The paper analyzes the grating parameters such as the period, depth, fill groove that influence the diffraction efficiency of the grating. The TM mode diffraction efficiency is more than 95%, and the TE mode diffraction efficiency is less than 5%, the pyramidal sub-wavelength polarizer grating has good polarizer performance than others shapes in the optical communication band of 1550nm. In this paper, we designed this kind of sub-wavelength grating polarizer has great potential applying in optical switching, optical memory, optical detectors and other photo-electronic devices.

Rigorous Coupled Wave Analysis for Plasmonic Nanoparticles

2017 ◽  
Vol 866 ◽  
pp. 341-344
Author(s):  
Suejit Pechprasarn ◽  
Acharawan Panlomso ◽  
Suttipong Aiam-Um ◽  
Phitsini Suvarnaphaet ◽  
Sani Boonyagul ◽  
...  
Keyword(s):  
Field Enhancement ◽  
Computation Time ◽  
Spherical Shape ◽  
Wave Analysis ◽  
Rigorous Coupled Wave Analysis ◽  
Speed Up ◽  
Key Issues ◽  
Pros And Cons ◽  
Rigorous Coupled Wave ◽  
Coupled Wave

Electromagnetic simulation packages for nanoparticles have become of interest for science and engineering community because of interesting properties of nanomaterials, such as, plasmonics and localized field enhancement. There are several approaches to calculate electromagnetic wave responses including time domain and frequency domain; each approach does have its own pros and cons. In this paper, we discuss basic principle of Rigorous coupled wave analysis (RCWA) and some key issues of 2D Rigorous Coupled Wave Analysis (RCWA) for nanoparticle simulation, such as, the computing demands (long computation time and memory consumption) and staircase approximation. We also suggest some feasible approaches to get around the issues and speed up the calculation, such as, employing Li Feng Li’s RCWA algorithm for circular and elliptical rods, making use of the symmetry of spherical shape particles to reduce redundancies in computation and building up an Eigenvector/Eigenvalue database of difference radii of disks, so that these disks can be stacked together to form various sizes of nanospheres.

scholarly journals TiO2 Self-Assembled, Thin-Walled Nanotube Arrays for Photonic Applications

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1332 ◽  
Author(s):  
Christin David
Keyword(s):  
Field Enhancement ◽  
Front Surface ◽  
Electrochemical Anodization ◽  
Surface Reflection ◽  
Rigorous Coupled Wave Analysis ◽  
Thin Walled ◽  
Rigorous Coupled Wave ◽  
Carrier Doping ◽  
Foil Substrate ◽  
Additional Charge

Two-dimensional arrays of hollow nanotubes made of TiO 2 are a promising platform for sensing, spectroscopy and light harvesting applications. Their straightforward fabrication via electrochemical anodization, growing nanotube pillars of finite length from a Ti foil, allows precise tailoring of geometry and, thus, material properties. We theoretically investigate these photonic crystal structures with respect to reduction of front surface reflection, achievable field enhancement, and photonic bands. Employing the Rigorous Coupled Wave Analysis (RCWA), we study the optical response of photonic crystals made of thin-walled nanotubes relative to their bare Ti foil substrate, including under additional charge carrier doping which might occur during the growth process.

scholarly journals Extraordinary Optical Transmission by Hybrid Phonon–Plasmon Polaritons Using hBN Embedded in Plasmonic Nanoslits

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1567
Author(s):  
Shinpei Ogawa ◽  
Shoichiro Fukushima ◽  
Masaaki Shimatani
Keyword(s):  
Optical Transmission ◽  
Hexagonal Boron Nitride ◽  
Incident Angle ◽  
Optical Filters ◽  
Extraordinary Optical Transmission ◽  
Light Manipulation ◽  
Rigorous Coupled Wave Analysis ◽  
Fabry Perot ◽  
Hyperbolic Dispersion ◽  
Rigorous Coupled Wave

Hexagonal boron nitride (hBN) exhibits natural hyperbolic dispersion in the infrared (IR) wavelength spectrum. In particular, the hybridization of its hyperbolic phonon polaritons (HPPs) and surface plasmon resonances (SPRs) induced by metallic nanostructures is expected to serve as a new platform for novel light manipulation. In this study, the transmission properties of embedded hBN in metallic one-dimensional (1D) nanoslits were theoretically investigated using a rigorous coupled wave analysis method. Extraordinary optical transmission (EOT) was observed in the type-II Reststrahlen band, which was attributed to the hybridization of HPPs in hBN and SPRs in 1D nanoslits. The calculated electric field distributions indicated that the unique Fabry–Pérot-like resonance was induced by the hybridization of HPPs and SPRs in an embedded hBN cavity. The trajectory of the confined light was a zigzag owing to the hyperbolicity of hBN, and its resonance number depended primarily on the aspect ratio of the 1D nanoslit. Such an EOT is also independent of the slit width and incident angle of light. These findings can not only assist in the development of improved strategies for the extreme confinement of IR light but may also be applied to ultrathin optical filters, advanced photodetectors, and optical devices.

Rigorous Coupled Wave Analysis of Surface Plasmon Resonance Sensor Based on Metallic Grating

2011 ◽  
Vol 211-212 ◽  
pp. 465-468
Author(s):  
De Wei Chen
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Diffraction Order ◽  
Wave Analysis ◽  
Metallic Grating ◽  
Rigorous Coupled Wave Analysis ◽  
Resonance Sensor ◽  
Rigorous Coupled Wave ◽  
Coupled Wave

Since the development almost a decade ago of the first biosensor based on surface plasmon resonance (SPR), the use of this technique has increased steadily. In this study, we theoretically investigated the sensing character of SPR sensor with reflection type metallic with Rigorous Coupled Wave Analysis (RCWA) method, and the mechanism is analyzed by the field distribution. It is found that the sensitivity of negative diffraction order, which goes higher quickly as the resonant angle increases, is much greater than that of positive diffraction order.

scholarly journals Holographic Polymer-Dispersed Liquid Crystals: Materials, Formation, and Applications

2008 ◽  
Vol 2008 ◽  
pp. 1-52 ◽  
Author(s):  
Y. J. Liu ◽  
X. W. Sun
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Refractive Index Profile ◽  
Single Step ◽  
Fast Switching ◽  
Polymer Dispersed Liquid Crystal ◽  
Current State ◽  
Index Matching ◽  
Polymer Dispersed ◽  
Materials Used

By combining polymer-dispersed liquid crystal (PDLC) and holography, holographic PDLC (H-PDLC) has emerged as a new composite material for switchable or tunable optical devices. Generally, H-PDLC structures are created in a liquid crystal cell filled with polymer-dispersed liquid crystal materials by recording the interference pattern generated by two or more coherent laser beams which is a fast and single-step fabrication. With a relatively ideal phase separation between liquid crystals and polymers, periodic refractive index profile is formed in the cell and thus light can be diffracted. Under a suitable electric field, the light diffraction behavior disappears due to the index matching between liquid crystals and polymers. H-PDLCs show a fast switching time due to the small size of the liquid crystal droplets. So far, H-PDLCs have been applied in many promising applications in photonics, such as flat panel displays, switchable gratings, switchable lasers, switchable microlenses, and switchable photonic crystals. In this paper, we review the current state-of-the-art of H-PDLCs including the materials used to date, the grating formation dynamics and simulations, the optimization of electro-optical properties, the photonic applications, and the issues existed in H-PDLCs.

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